Three Cornered Leek Soup

11 Jan Watercress and Three-Cornered Leek Soup

A Happy New Year to you all……….. I’m slightly late in getting that seasonal wish and this new blog out there because we’ve been flat out doing Really Wild Festival work and getting our act together for the judging of the Countryside Alliance Awards in which we are finalists … (so exciting!).

Down here on the coast in Pembrokeshire I’m fortunate to be able to pick wild food through every season. Even at its coldest I can pick Alexanders, sea beet and three cornered leek, sorrel, crow garlic and so on. I do foraging walks for the Pembrokeshire Coast National Park every Thursday throughout the year, but rarely get people turning out during the winter, mostly because they imagine that there is nothing about.

My calendar of courses and walks are on my website now. It always takes longer that I imagine because of sorting tides and times and days! I get enquiries all year from visitors who are keen to get onto the seashore forage but it’s often impossible to fit in with any tide times during their stay. I can usually manage private hedgerow forages at the drop of a hat, and those are always fun…. exploring the lanes around St Davids Cathedral Close and the Bishop’s Palace.

I wasn’t going to mention the weather, but it is difficult not to … there are places in Great Britain where people are struggling in horrendous situations in badly flooded areas. I’m so glad I no longer keep sheep and horses … it’s bad enough in our average winter but is nearly impossible in these hostile conditions.

I’ve chosen a simple recipe to celebrate two plants, one that likes water and another that is very common here at this time of year, watercress and three cornered leek. There is also the option of using seaweed or potato to thicken the soup ….do try the seaweed if you have the chance.

The fresh bright green of wild watercress (Nasturtium officinale) always seems to herald the spring, but it is available throughout most of the year. Although it has been grown commercially in watercress beds for approximately 100 years, this rapidly growing aquatic or semi-aquatic perennial can be gathered from streams and damp areas throughout the countryside.

If there have been any cattle, or more particularly sheep, grazing nearby it is unwise to collect and eat it fresh from the wild as it might be harbouring parasites such as the liver fluke (Fasciola hepatica). However, it’s perfectly fine to pick this fantastic ingredient and cook with it.

Wild watercress has a stronger flavour than its cultivated brother, and is thought superior in many ways. Always cut it, don’t pull it up by the roots, and don’t discard the stems which can be steamed and served as a vegetable.

It is one of the oldest known leaf vegetables consumed by humans and contains vitamins A, K and E and B6, and more vitamin C gram for gram than oranges.


Three cornered leek (Allium triquetrum) is non-native and pretty invasive! It is such a useful plant and one I use all the time whilst it is in season. It has pretty white flowers and the whole plant is edible. It tastes fairly garlicky but not as strong as wild garlic. It can often grow amongst snowdrops, daffodils and bluebells so care must be taken when picking the leaves which all look a little similar. Sniffing the cut end of the leaves is the quickest way to work out what you are picking with this plant. The flowers are great sprinkled on salads and their stalks shouldn’t be wasted either. I cook three cornered leek and eat it raw instead of spring onions.

three cornered leek

Watercress and Three-Cornered Leek Soup


  • Two good bunches watercress, stems removed.
  • Two good bunches three cornered leek leaves
  • 1oz butter
  • 1 tbsp of oil
  • 5g dried Carragheen seaweed to thicken (or 1 medium potato, sliced)
  • 1L chicken/vegetable stock
  • Cream to finish.


  • Chop the three-cornered leeks and watercress.
  • Soak the carrageen in water until soft.
  • Fry the three-cornered leek gently in the butter, then add the stock and the carrageen and/or potato.
  • Bring to the boil, and then reduce heat pressing the carrageen against the side of the pan every so often.
  • When the liquid has begun to thicken then add the watercress and simmer for about 15 mins.
  • Whizz in a blender and serve. Pour a little cream on top if preferred.

The Carragheen (Chrondus crispus) can either be tied loosely in a piece of muslin so that it can be removed at the end of cooking or left in and whizzed up with the soup. I always leave it in.

Leek or onion can be used instead of the three cornered leek, and potato to thicken instead of the seaweed.